It was raised to 16 in 1885 as part of the
Criminal Law Amendment as protection at the time from children being sold into prostitution. The idea was very much campaigned for by the social purity movement who believed in abstinence from sex for both men and women - until marriage. This amendment also made any homosexual engagement between men illegal.
Different countries have different ages of consent. Who is right?
I do think if a bloke thinks a young woman is under age, he is best to avoid her advances. However I knew a 12 year olds who have convinced an 18 yr olds that she are 16. And a couple of 15 yr olds girls who were working through the 18/19 year olds. And one girl in sixth form who liked older men - she was 17 seeing a 30 year old - she is married to Dr Fox now
(same age gap)
It's complex. Young women - especially the school girl look are seen as attractive - the virgin who is up for it.